A hydraulic pump assembly of the type referred to above is disclosed in WO 2010/019094 (corresponding to copending Swedish Patent Application No 0801794-9 from the same applicant). The objects of the assembly shown therein are in principle the same as for the present invention, namely to reduce the number of components, to simplify the assembly, to reduce the weight and the space requirement for the assembly, and to keep the production and assembly costs as low as possible. Further, there is a desire to create a simple but highly reliable actuation system for a limited slip coupling in a torque distribution system for example for all wheel drive vehicles having the shortest possible reaction time for control signals.
The said application represented a first development stage for a greatly improved assembly, but development work has continued resulting in a truly integrated assembly even better fulfilling the above objects than the previous assembly.